Your post begs a great many questions and you need to provide more information if you want others to help you.
How do you know that Edward Mackay was a fisherman from Durness and that he was in Badcall Inchard in 1881? (These two places are quite far apart - opposite sides of the county, in fact.) Have you found Edward Mackay and/or Christina Horsburgh in the 1881 census or in any other censuses? (Censuses will give you their ages, marital status, occupations and birthplaces.) Have you looked for a possible marriage certificate? What were the names, dates and places of birth of their children? Where did you find the names of Christina Horsburgh's parents?
You can look on ScotlandsPeople (
www.scotlandspeople.gov.uk) for help in answering these and other questions. It's a pay-per-view site, but modestly priced and you can download digital images of original documents instantly. (The indexes are free to view once you have registered.)
I hope this helps.
Margow